diff --git a/.gitignore b/.gitignore
index f0f7e07..805c2eb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -66,3 +66,6 @@ common_libs/tests/compare_pairing
 common_libs/tests/diag_synthetic
 common_libs/tests/diag_automata_validation
 common_libs/tests/diag_tm_pattern_offline
+
+# Primary source archive kept locally, NOT tracked (12 MB)
+docs/BitBrain_C_code.zip